Single-layer graphene-TiO2 nanotubes array heterojunction for ultraviolet photodetector application

In this work, we reported on the fabrication of a single-layer graphene (SLG)-TiO₂ nanotube arrays (NTs) heterostructures ultraviolet photodetector (UVPD) by transferring chemical vapor deposition derived MLG on the surface of anodic TiO₂NTs array. Through varying the annealing atmosphere and anodization time in the TiO₂ synthesis procedure, the electronic and optoelectronic properties of the as-fabricated Schottky junction UVPD were studied. It was revealed that the anodic TiO₂NTs annealed in air showed a better rectifying behavior and was highly sensitive to UV light irradiation. Further investigation found that the device performance of the UVPD can be readily modulated by the anodization time, and the anodic TiO₂NTs with a medium tube length of 9.6 μm exhibits the highest device performance. These results demonstrated that the present SLG-TiO₂NTs array hetero-junction UVPD will be highly promising for fabricating high-performance optoelectronic device and system in the future.